Therapeutic pack for thermal applications

ABSTRACT

A therapeutic pack containing chemicals to produce a temperature-changing chemical reaction, e.g. endothermic or exothermic. The chemical components for the reaction are held spaced apart within a bag by a fracturable means, e.g. a diaphragm. The bag incorporates an insulation cover, e.g. minutely expanded polystyrene paper and aluminum foil, various portions of which may be selectively removed to provide an effective heat-transfer path of a predetermined size, to accomplish the desired therapeutic treatment.

United States Patent Caillouette Feb. 22, 1972 [54] THERAPEUTIC PACK FOR THERMAL 3,149,943 9/1964 Amador ..128/402 X APPLICATIONS 3,175,558 3/1965 Caillouette et al. ..l28/403 3,463,161 8/1969 Andrassy ..l28/402 [72] inventor: James C. Caillouette, Pasadena, Calif.

73 Ass ee: Ka Laboratories Inc. San Die 0, Cali. Primary aPP 22: Fl A y 4 1969 g I Attorney-Smyth,Roston&Pavitt ie pr.

[21] Appl. No.: 813,491 ABSTRACT T A therapeutic pack containing chemicals to produce a tern perature-changing chemical reaction, e.g. endothermic or exlll othermia The chemic 31 components for the reaction are held [58] i 254 spaced apart within a bag by a fracturable means, e.g. a

' i diaphragm. The bag incorporates an insulation cover, e.g. minutely expanded polystyrene paper and aluminum foil, various portions of which may be selectively removed to provide [56] References cued an effective heat-transfer path of a predetermined size, to ac- UNTTED STATES PATENTS complish the desired therapeutic treatment. 2,573,791 11/1951 Howells ..l28/402 X 8 Claims, 4 Drawing Figures THERAPEUTIC PACK FOR THERMAL APPLICATIONS BACKGROUND AND SUMMARY OF THE INVENTION It is well known that coldpacks are effective to avoid the usual swelling that accompanies many human injuries. Such an application also helps to relieve the pain to some extent. Somewhat similarly, in the treatment of various other maladies, hotpacks also have therapeutic value.

Although various forms of thermal therapeutic packs have been proposed in the past, certain disadvantages have generally been attendant each form. For example, icepacks normally necessitate the use of padding to cushion the ice on its application to painfully sensitive tissue. Additionally, in some environments, it is difficult to preserve crushed ice available for use in a coldpack. Other forms of traditional packs, e.g., towels that have been heated or chilled, are frequently difficult to obtain and are effective, at best, for only a brief interval.

Somewhat recently, chemical therapeutic packs have been proposed which accomplish elevated or reduced temperatures by endothermic or exothermic chemical reaction. For example, it has been proposed to contain the components for such a reaction within a plastic bag separated from each other by an imperforate membrane. Then by providing one of the components in a somewhat fluid state (liquid or semiliquid) that component may be pressurized sufficiently to burst the separating membrane simply by manually squeezing the bag. As a consequence, the components of the thermal reaction become intimate and accomplish the desired temperature change providing a convenient therapeutic pack.

Although chemical therapeutic packs have proven to be somewhat useful, certain disadvantages have restricted the extent of their use. Such packs have been proposed which attain temperatures that are sufficiently low or high however, the period during which they are effective is very short. That is, although chemical therapeutic packs as previously proposed are convenient they have such a limited period of effective application that their use has been quite restricted. Consequently, a considerable need exists for an improved therapeutic thermal pack which may be conveniently and easily transported and stored, and which may be prepared for use in a matter of seconds to provide cold or heat to a specific body location for an effective interval of time.

In general, the present invention comprises a chemical therapeutic pack incorporating a bag which not only contains the components for a chemical reaction but additionally control the pattern of heat flow to effectively increase the useful period of the thermal pack. Packs incorporating the present invention may afford considerable selectively in the shape and size of the body area which is to be treated, accomplished by selective removal ofdefined portions of an insulating layer.

BRIEF DESCRIPTION OF THE DRAWING In the drawings, which constitute a part of this specification, exemplary embodiments exhibiting various objectives and features hereof are set forth, specifically:

FIG. 1 is a. trimetric view of a therapeutic pack incorporating the principles of the present invention;

FIG. 2 is a sectional view taken through the pack of FIG. 1;

FIG. 3 is an enlarged sectional view of a fragment of the structure of FIG. 2; and

FIG. 4 is a bottom plan view of the pack ofFIG. 1.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT Referring initially to FIG. 1, there is shown a pack P constructed in accordance with the present invention. As indicated, packs in accordance with the present invention may be employed to apply heat or cold to a patient, depending upon whether the pack contains the chemical components for an endothermic or an exothermic temperature-changing reaction. Chemical components for both types of reaction appropriate for use in the pack I are well known in the prior art.

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The detailed structure of the pack P is best illustrated by the sectional view of FIG. 2. An upper sheet 12 of flexible imperforate material is edge sealed to a sheet 14 providing a closed interior 16. The interior 16 of the bag or pack is divided into two separate compartments 18 and 20 by a fracturable diaphragm 22. The compartment 18 contains a fluid chemical component 24 while the compartment 20 is partly filled by a solid chemical component 26. If, for example, the pack is to produce cold, the component 24 may comprise water while the component 26 includes ammonium nitrate. Alternatively, if the pack is to produce heat the component 24 may comprise water while the component 26 comprises calcium chloride. Of course various additives and other components may be employed as well known in the prior art.

The fracturable diaphragm 22 is formed to resist only limited fluid pressure by way of comparison to the sheets 12 and 14. For example, the diaphragm may comprise a thin film of polyethylene which will fracture on application of squeezing pressure to the liquid component 24.

It is to be appreciated that the basic fracturable diaphragm arrangement is well known in the prior art and that a wide variety of other structural arrangements are well known and readily adaptable to the present invention. Functionally, the objective merely is to provide a division or separation between the two chemical components 24 and 26, of the reaction, which may be fractured by manually exerting pressure upon the liquid or semiliquid component 24. Of course, when the diaphragm 22 is fractured the chemical components become intimate and enter the desired temperature-changing reaction.

The sheets 12 and 14, comprising the exterior of the pack P are each laminates incorporating several separate layers as shown in FIGS. 2 and 3. The outer layers 28 comprise an insulating material, e.g., minutely expanded polystyrene, which layers are laminated to a reflective material forming the internal layers 30, e.g., aluminum foil. The layers 30 are in turn backed by imperforate film layers 32, e.g., polyethylene. This laminate may be accomplished as well known in the prior art by the use of heat, pressure, adhesives and so on in various combinations. However, to facilitate the use of the structure, as set forth in detail below, it is important to note that the bond between the center layer 30 and the internal layer 32 is of a releasable nature.

The structure of the sheets 12 and 14 is shown in somewhat greater detail in the grossly enlarged via of FIG. 3. Referring to that figure the layers 28 and 30 are shown secured together by an adhesive bond 34 which is permanent. However, the layer 30 is secured to the layer 32 by a releasable adhesive bond 36 as widely used in the tape arts for releasable hacking sheets. As a consequence, segments of the sheet 14 may be removed along transverse separations 38 simply by lifting the layers 28 and.30 from the layer 32.

The transverse separations 38 (FIG. 3) are provided to define various closed areas as shown in FIG. 4, on the underside of the pack. Specifically, as indicated by dashed lines, areas 40, 42, 44 and 46 are defined by closed cuts of the separations 38, In this regard, each of the areas 40, 42, 44 and 46 carries a lift tab, specifically tabs 48, 50, 52 and 54 respectively.

In the manufacture of a product embodying the present invention as disclosed in the figures, the individual sheets 12 and 14 may be initially laminated in large sizes then cut to size. Specifically, the sheet 12 simply comprises a laminate of the individual unitary layers 28, 30 and 32, cut into a sheet of approximately 6 8 inches for example. The lower sheet 14 (as shown) incorporates a unitary layer 28; however, the layers 30 and 32 as indicated above, are served by separations 38 which define-the areas 40, 42,44 and 46. Various cutting techniques well known in the prior art may be employed to accomplish these cuts or separations 38, with the result that the layers 30 and 32 are either completely or substantially severed by the separations. I

With the completion of the individual sheets 12 and 14. as by lamination and die-cutting techniques, these two sheets are first joined together by an initial preliminary sealing operation. Specifically, for example, the sheets may be sealed together along three edges 58, 59 and 60 (by various techniques as heat, pressure or adhesive methods). Thereafter, the solid component 26 (FIG. 2) is placed in the partially closed bag and the diaphragm 22 is sealed therein so as to provide an air space in the interior compartment 20. Subsequently, the semiliquid or liquid component 24 is placed in the compartment 18 to substantially fill that compartment, after which the edges 62 (FIG. 4) are sealed closed. The unit may be provided with an additional package for protection and in such a form may be stored for a long period of time or transported through environments which may be relatively extreme.

The major contemplated use for the structure as disclosed herein is in the treatment of human maladies. For example, cold applications to the perineum in post delivery pregnancies has been found extremely effective. Additionally, the prompt application of cold to various bodily injuries is a widely accepted form of treatment that is in widespread use. Somewhat similarly, the application of heat is also to have therapeutic value for many maladies.

Generally, the area to be thermally treated depends upon the nature of the malady. Consequently, in some instances, it is desirable to treat a very small area while in other instances a large area is to be treated. Additionally, variously shaped areas must be accommodated. in using the structure as disclosed herein, a portion of the layers 28 and 30 is removed from one of the areas 40, 42, 44 or 46, depending upon the area tobe treated. This is accomplished simply by pulling the tab of the selected area for removal.

Of course, it is apparent that removal of the layers from the area 40 provides a long narrow exposed area, while at the other extreme, removal of the layers from the area 46 affords a large oval area. In any event, the area which has the exterior layers removed provides an effective heat-transfer .path through which heat may flow either from the body or to the body, depending upon the type of thermal pack in use. That is, the area from which the exterior layers are removed affords a discrete heat-transfer path while insulation is provided to block the flow of heat through the remainder of the pack. As a consequence, the pack can be held by hand on the area to be treated without discomfort to the holder. However, more significantly, as the major heat-transfer path is limited to the area to be treated, the effective period for the pack is greatly prolonged. For example, if the pack is used to treat a relatively small injury, it will remain effective for a prolonged period of use.

After removing the outer layers from the selected area of the pack, the pack is further prepared for use by squeezing it in such a manner as to exert pressure on the semiliquid or liquid component 24, thereby causing the diaphragm 22 to burst. This operation may be easily performed by hand so that the component 24 forces the diaphragm 22 into the airspace provided in the compartment 20 to an extent beyond the yield point of the diaphragm 22 so that it fractures. Subsequently, the package may be kneaded briefly so that the components 18 and 20 are intimately mixed during a reaction period which as indicated above is either exothermic or endothermic. As a consequence, the pack changes temperature preparatory to a period ofthermal treatment.

In the operation of kneading of the pack, as well as in its use, it is important that the sheets 12 and 14 be relatively flexible and compliant. Consequently, in this regard, it has been found advisable to employ layers which can tolerate a complete fold without fracture. Of course, metal foils and plastic films of such flexibility are readily available. Additionally, thermal insulating material is also available in the form of microscopically expanded polystyrene or fabricated paper which may incorporate a binder material as well known in the prior art.

From the above, it is apparent that the system hereof may be utilized to provide therapeutic thermal packs which may be inn radically conveniently and easily stored and transported and are ready for use with slight preparation. Additionally, the packs are effective for a significant period and may be economically manufactured.

What is claimed is:

l. A therapeutic pack for thermal heat treatment, including:

a containing bag of flexible material, the bag including at least a pair of layers one of which is reflective to heat along at least particular portions of the bag,

chemical means within the bag including components for producing a thermal reaction, at least a particular one of the components being mobile for mixture with other components to provide a thermal reaction between the components, and

fracturable means disposed within the bag for defining at 'least a pair of compartments for holding the particular component in one compartment and other components in the other compartment, the fracturable means being fracturable upon the exertion of pressure against the bag to provide for a mixture of the mobile component with other components, the reflective layer being removable from the other layer of the bag at a selected position on the bag to provide for a concentration of the thermal treatment at the selected position.

2. A therapeutic pack for thermal heat treatment, including,

a containing bag of flexible material, the bag including along particular portions of the bag at least three layers respectively constituting an external layer, an intermediate layer and an inner layer, the intermediate layer being heat reflective and the inner layer being imperforate,

chemical means within the bag including at least a pair of components for producing a thermal reaction, one of the components being mobile to provide a mixing with the other component and to provide the thermal reaction in accordance with such mixing, and

boundary means disposed relative to the bag to define within the bag two isolated compartments one for holding the mobile component and the other for holding the other component, the boundary means being responsive to the exertion ofa force to become fractured for the movement of the mobile component into mixed relationship with the other component, the external layer and the reflective layer being removable from the inner layer at a selected portion of the bag to provide for a concentration of the thermal heat treatment at such selected portion.

3. A pack for thermal heat treatment, including,

a first sealed container formed from at least a pair of layers along at least a portion of the container, at least one of the layers being heat reflective,

a first chemical disposed within the container,

a compartment sealed relative to the container and having a fracturable surface facing the first chemical in the container, and

a second chemical disposed within the second container and having properties of mixing with the first chemical upon a fracture of the compartment and of reacting chemically with the first chemical to provide a thermal reaction, at least a selected portion of the heat reflective layer being removable from the container to provide for a concentration of the thermal heat treatment at such selected portion.

4. A pack for thermal heat treatment, including,

a first sealed container formed from at least a pair of layers along at least a portion of the container, at least one of the layers being heat reflective,

a first chemical disposed within the container.

a compartment sealed relative to the container and having a fracturable surface facing the first chemical in the container, and

a second chemical disposed within the second container and having properties of mixing with the first chemical upon a fracture of the compartment and of reacting chemically 5. The therapeutic pack set forth in claim 2 wherein the intermediate layer is made from a metallic foil. 6. The therapeutic pack set forth in claim 2 wherein the external layer is made from a material having a relatively low heat conductivity. 7. The pack set forth in claim 4 wherein the intermediate layer is made from a metallic foil. 8. The therapeutic pack set forth in claim 1 wherein the reflective layer is made from a metal foil. 

2. A therapeutic pack for thermal heat treatment, including, a containing bag of flexible material, the bag including along particular portions of the bag at least three layers respectively constituting an external layer, an intermediate layer and an inner layer, the intermediate layer being heat reflective and the inner layer being imperforate, chemical means within the bag including at least a pair of components for producing a thermal reaction, one of the components being mobile to provide a mixing with the other component and to provide the thermal reaction in accordance with such mixing, and boundary means disposed relative to the bag to define within the bag two isolated compartments one for holding the mobile component and the other for holding the other component, the boundary means being responsive to the exertion of a force to become fractured for the movement of the mobile component into mixed relationship with the other component, the external layer and the reflective layer being removable from the inner layer at a selected portion of the bag to provide for a concentration of the thermal heat treatment at such selected portion.
 3. A pack for thermal heat treatment, including, a first sealed container formed from at least a pair of layers along at least a portion of the container, at least one of the layers being heat reflective, a first chemical disposed within the container, a compartment sealed relative to the container and having a fracturable surface facing the first chemical in the container, and a second chemical disposed within the second container and having properties of mixing with the first chemical upon a fracture of the compartment and of reacting chemically with the first chemical to provide a thermal reaction, at least a selected portion of the heat reflective layer being removable from the container to provide for a concentration of the thermal heat treatment at such selected portion.
 4. A pack for thermal heat treatment, including, a first sealed container formed from at least a pair of layers along at least a portion of the container, at least one of the layers being heat reflective, a first chemical disposed within the container, a compartment sealed relative to the container and having a fracturable surface facing the first chemical in the container, and a second chemical disposed within the second container and having properties of mixing with the first chemical upon a fracture of the compartment and of reacting chemically with the first chemical to provide a thermal reaction, the first sealed container has an external layer, an intermediate layer and an inner layer and wherein the external layer is made from a material having a relatively low heat conductivity, the intermediate layer is heat reflective and the inner layer is imperforate, the external layer and the intermediate layer being adhered to the inner layer but are removable from the inner layer at a selected position to provide for a concentration of the thermal heat treatment at the selected position.
 5. The therapeutic pack set forth in claim 2 wherein the intermediate layer is made from a metallic foil.
 6. The therapeutic pack set forth in claim 2 wherein the external layer is made from a material having a relatively low heat conductivity.
 7. The pack set forth in claim 4 wherein the intermediate layer is made from a metallic foil.
 8. The therapeutic pack set forth in claim 1 wherein the reflective layer is made from a metal foil. 